A call-unit count device according to the present invention comprises a memory circuit having a high-order level and a low-order level composed of n (n: integer greater than or equal to 2) bits and wherein all the bits each indicative of the initial value and placed in the low-order level are changed to reversed values bit by bit each time a one call-unit add command is given, all the bits in the low-order level, which have been brought to the reversed values, are returned to the initial value bit by bit each time the one call-unit add command is given, and values stored in the high-order level are changed upon a carry from the low-order level to the high-order level.